When a reference type is not resolved, the new javadoc does a compiler imitation and crashes out with a fatal error. The old Javadoc carried on and generated a warning message only.

Please find the behaviour attached.
===================================
jtools-sqe:/home/vr128054/jd-tests/newjavadoc/tests/regression 63 % javadoc D.java
Loading source file D.java...
Constructing Javadoc information...
D.java:3: cannot resolve symbol
symbol : class RRR
location: class D
        public void foo(RRR rrr) {}
                        ^
1 error


Please find the testcase attached.
=================================
public class D {

        public void foo(RRR rrr) {}
}


While it is perfectly valid for the compiler to report an error, it may not be so for Javadoc. Javadoc being a documentation tool can just generate a warning and proceed as in Old Javadoc.